Simultaneous measurements of velocity and deformation in flows through compliant diaphragms

Amatya, Devesh; Longmire, Ellen

doi:10.1016/j.jfluidstructs.2009.12.001

Cited by 9 publications

(3 citation statements)

References 19 publications

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“…Typical NaI solutions matching the RI of PMMA have concentrations in the range of 60.0-64.8 wt%, yielding a RI in the range 1.485-1.491 (Imao et al 1996;Parker and Merati 1996;Uzol et al 2002;Mehta et al 2007;Uzol et al 2007;Soranna et al 2008;Yuki et al 2008;Wu et al 2009;Amatya and Longmire 2010;Wu et al 2011Wu et al , 2012Yuki et al 2011;Yuan et al 2012;Tomac and Gregory 2014). A detailed study of the use of NaI for RI matching (aimed at PIV measurements) over an even wider RI range (1.330-1.510) was performed by Bai and Katz (2014), who also matched NaI solutions to three optical solids formed from resins with RIs in the range 1.495-1.508.…”

Section: Aqueous and Hydrophilic Liquidsmentioning

confidence: 99%

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

2017

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Experimental techniques based on optical measurement principles have experienced significant growth in recent decades. They are able to provide detailed information with high-spatiotemporal resolution on important scalar (e.g., temperature, concentration, and phase) and vector (e.g., velocity) fields in single-phase or multiphase flows, as well as interfacial characteristics in the latter, which has been instrumental to step-changes in our fundamental understanding of these flows, and the development and validation of advanced models with ever-improving predictive accuracy and reliability. Relevant techniques rely upon well-established optical methods such as direct photography, laser-induced fluorescence, laser Doppler velocimetry/phase Doppler anemometry, particle image/tracking velocimetry, and variants thereof. The accuracy of the resulting data depends on numerous factors including, importantly, the refractive indices of the solids and liquids used. The best results are obtained when the observational materials have closely matched refractive indices, including test-section walls, liquid phases, and any suspended particles. This paper reviews solid–liquid and solid–liquid–liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid–liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330–1.620 and 1.251–1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials in single-phase liquid or multiphase liquid–liquid flow systems. In addition, the refractive indices of fluids can be further tuned with the use of additives, which also allows for the matching of important flow similarity parameters such as density and viscosity

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Section: Aqueous and Hydrophilic Liquidsmentioning

confidence: 99%

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

2017

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“…There are several clinical trials focused on the wavepropagation phenomenon [35] and experimental studies of flow fields in low α regimes through compliant models [36] - [38], but there are few ex-vivo experimental studies that take into account the effects of aortic compliance on the flow fields in a near-physiological regime.…”

Section: A Literature Reviewmentioning

confidence: 99%

Experimental Investigation Of The Effect Of Compliance Properties On The Flow In An Analogous Ex-Vivo Heart Perfusion System

Bessa¹,

Hadfield²,

Chung³

et al. 2021

Progress in Canadian Mechanical Engineering. Volume 4

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The heart transplant waiting list far exceeds supply. This shortage is generally attributed to the high number of discarded hearts and to the narrow six-hour time window currently available through the standard preservation method: static cold storage (SCS). An alternative method called exvivo heart perfusion (EVHP) maintains a human donor heart beating outside the body for the time preceding transplantation surgery. By keeping the heart working in a physiologically consistent way and monitoring its functions, the organ's health can be assessed and the transplant time window can be extended. In order to improve and optimize the EVHP system, the present work aims to further investigate the relationship between pulsatile flow and compliance by assessing the effect of different compliant tubes on the upstream and downstream pressure and flow fields. Hence, silicone tubes of variable compliance, length, and geometrical shape were developed for this studyalthough only one sample has been tested so far, in addition to an experimental setup containing a hydraulic circuit analogous to the left flow loop of the EVHP system. The flow fields downstream of the compliant section are assessed using laser Doppler velocimetry (LDV). Findings will include novel visualizations of these flow fields as well as comparisons of pressure waveforms from an assortment of compliance conditions.

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“…The compliant response of the aorta has a significant impact on wave propagation effects in-vivo and therefore is widely recognized as being a clinically important marker for overall cardiovascular health [ 43 – 46 ]. There have been several clinical investigations into wave propagation effects in-vivo [ 47 ], and experimental investigations into flow fields through compliant phantoms in low α regimes [ 48 – 50 ], but, to the authors’ knowledge, there has been little experimental investigation into controlled changes in aortic compliance within a physiological range in an ex-vivo environment. There has been a great deal of research into understanding velocity distributions through compliant phantoms using PIV or particle tracking velocimetry (PTV) in cardiovascular flow regimes [ 38 , 48 , 49 , 51 ], including the effect of certain pathophysiology such as stenosis [ 52 , 53 ], in compliant pulsatile flow regimes through the use of stereo-PIV and time-resolved PIV.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation into the effect of compliance of a mock aorta on cardiac performance

et al. 2020

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Demand for heart transplants far exceeds supply of donated organs. This is attributed to the high percentage of donor hearts that are discarded and to the narrow six-hour time window currently available for transplantation. Ex-vivo heart perfusion (EVHP) provides the opportunity for resuscitation of damaged organs and extended transplantation time window by enabling functional assessment of the hearts in a near-physiologic state. Present work investigates the fluid mechanics of the ex-vivo flow loop and corresponding impact on cardiac performance. A mechanical flow loop is developed that is analogous to the region of the EVHP system that mimics in-vivo systemic circulation, including the body's largest and most compliant artery, the aorta. This investigation is focused on determining the effect of mock aortic tubing compliance on pump performance. A custom-made silicone mock aorta was developed to simulate a range of in-vivo conditions and a physiological flow was generated using a commercial ventricular assist device (VAD). Monitored parameters, including pressure, tube distension and downstream velocity, acquired using time-resolved particle imaging velocimetry (PIV), were applied to an unsteady Bernoulli analysis of the flow in a novel way to evaluate pump performance as a proxy for cardiac workload. When compared to the rigid case, the compliant mock aorta case demonstrated healthier physiologic pressure waveforms, steadier downstream flow and reduced energetic demands on the pump. These results provide experimental verification of Windkessel theory and support the need for a compliant mock aorta in the EVHP system.

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Simultaneous measurements of velocity and deformation in flows through compliant diaphragms

Cited by 9 publications

References 19 publications

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

A review of solid–fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid–liquid and multiphase solid–liquid flows

Experimental Investigation Of The Effect Of Compliance Properties On The Flow In An Analogous Ex-Vivo Heart Perfusion System

Experimental investigation into the effect of compliance of a mock aorta on cardiac performance

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